In the first such case heard in court in France, grain grower Paul Francois, 47, says he suffered neurological problems including memory loss, headaches and stammering after inhaling Monsanto’s Lasso weedkiller in 2004. Previous health claims from farmers have foundered because of the difficulty of establishing clear links between illnesses and exposure to pesticides.

Francois and other farmers suffering from illness set up an association last year to make a case that their health problems should be linked to their use of crop protection products. The agricultural branch of the French social security system says that since 1996, it has gathered farmers’ reports of sickness potentially related to pesticides, with about 200 alerts a year. But only about 47 cases have been recognized as due to pesticides in the past 10 years. Francois, who suffers from neurological problems, obtained work invalidity status only after a court appeal.